I have a problem with an Arduino Due. When I connect a VNH5019 Motor Driver form Pololu in combination with 4 or more RPR220 lightsensors, the Arduino board instantly fries. The IC gets untouchably warm and the status lights slowly fade away. After 3 attempts to start the Arduino, all light is gone (when connecting to USB) and the Arduino is not recognized anymore. Also, after the Board is fried, Analog pins 4 en 5 are shorted with eachother AND the Ground and 5V ports. When I tried to use a VNH5019, the same things happened and the PWM port was shorted to Ground. I will attach a simple diagram showing the connections. What am I doing wrong??One 5V port is connected to ALL RPR220s and 2 VNH5019 (same goes for Ground). I already fried 5 (!) Due boards due to this problem.

Thanks in advance.

EDIT: This ONLY happens when I use a 11.1V battery connected throught VIN and GND. When using USB power I can use more than 7 RPR220s at the same time.

I changed the resolution. I do power everything from 3V3 but would that really be the cause of the frying, because it is not a problem when using USB power? I also tried to use 5V with the VNH5019s and only 3V3 with the RPR220s. That did also fry everything. Could the number of sensors connected to one port be the issue of the whole Arduino frying itself?

I want to know the answer as I am asking the forum. If you would have 5 dead Arduino Dues that wouldnt be nice right?Anyway, I dont want to do it wrong from now on so I am wondering what exactly to do to NOT fry the Arduinos anymore.Any help would be appreciated.

Firstly you mention 5V. Any 5V signal is totally incompatible with a Due input and canbe enough to trigger the symptoms described which are probably CMOS latch-up.

So absolutely no 5V signals to any signal pins at all is essential with the Due. Thismeans Vdd to the VNH5019 must be 3.3V.

The 3.3V power may not be up to the load - this is simething you can measure,power the VNH chip from a separate 3.3V supply and measure the current it takes,ditto for the opto-sensors. This means you'll be able to estimate the current draw.

The motor driver chip is the grey area for me - you haven't mentioned if its connectedup to a motor supply or motor or both - the circuit diagram doesn't show this. If it isconnected to another supply its essential to use separate ground wiring to the logicside.

At first, thank you very much. The VNH5019 is hooked up to 2 DC motors and it has an incoming supply voltage of 11.1V from the same battery used to power the Arduino (I have 2 VNh5019s with 3 motors total). Do I have to ground the VNH5019 seperately to battery ground only or to both the Due and the battery ground? Can I use a LLC to convert the 5V signals on the board (I rarely need those) to 3.3V and then just connect the VNH and the optosensors seperately?